Shop Lighting Upgrade

Brighter Lights

The bug to upgrade my shop bit.

My shop was formed piece by piece, without always thinking about how the shop would work best but more where can I fit this. It's easy to get complacent.

It's a brighter and whiter light. It's a world of difference.

I realized I was tired of how dim my shop was. When I moved in I had two incandescent bulbs, I added four for equal coverage and was amazed at how much brighter it was. The shine wore off and now I'm replacing all six with dual four foot T12 fixtures. While I like the idea of LED's, it's hard to beat the value of fluorescent fixtures.

The T12 dual fixture I installed.

Parts:

• (6) T12 48" fluorescent light fixtures - Utilitech MXL-101
• (12) T12 fluorescent light bulbs
• (6) 4" junction boxes
• (6) 4" junction box covers
• (8) strain relief connectors. You should be able to feed the wires through one knock out on most of the light. Since these are cheap, you could run in/out on opposite sides if preferred.
• 14 gauge 3 strand wire. You should be able to position your junction boxes so that you don't need additional wire, but you may need extra wire if things don't align
• (24) 1" Drywall screws to install boxes and lights to joists 
• (18) wire nuts - (3) for each light, both orange and yellow

Tools:

• Flat head screwdriver, phillips screwdriver, hammer, and pry bar to remove old fixtures
• Test Light to confirm that power is shut off and trouble shooting. With lights, as long as the switch is off power is cut, but it's best practice to flip the breaker just in case you absent mindedly flip the switch 
• Painters tape - I used this to mark light and junction box positions. You could mark on the joists with a pencil
• Drill with 5/32" bit for drywall screws
• Electrical tape
• Portable light(s) - you're switching the power off, you'll need auxiliary lights. You may need an extension cord.
• Phillips screwdriver for drywall screws and junction box covers
• Wire cutters  & wire strippers
• Pliers to straighten out wire ends and to remove knockouts
• A bucket or stool to reach joists

Price:

• $150 for lighting - I had wire nuts, screws, and lights already, so I spent $130.

Lighting
I have a Sketchup model of my shop, and measured out equal spacing for the new fixtures. With the garage door I had to keep the incandescent fixtures outside the path of travel, but the new fixtures aren't as deep so I can achieve better coverage.

I came across a lighting guide suggesting a minimum of 100 lumens per square foot. A 40-watt fluorescent bulb puts out about 2,200 lumens which means my upgrade increased my output to 26,400 total from 2,400. Incandescent bulbs put out 800 lumens.
My new set up put me at 100 lumens psf, two more lights would hit 130. I'm coming from 17 lumens psf so it's a big upgrade. You can never have too many lights, but determine the square footage of your shop and make sure you get at least 100 lumens.

The layout of the existing lights wasn't far off. I just centered them in the room, though I did have to rotate the middle two fixtures to accommodate ducting.

Preparation & Installation
I installed the junction boxes and lights before cutting power so I still had light to work. I had to rotate one of the center bay lights 90* due to ducting and rotated the other center bay light the same orientation for symmetry.

Pictures don't do it just. The top image is the incandescent lights, the middle
is the new lights installed but not connected, and the bottom is the new lights.
It's HUGE difference.

I tried to keep the junction box on one end of the light, but shifted a few boxes due to bracing or ducting and so that I wouldn't need more wire. Make sure your existing power wire will reach each junction box. If not, you'll need to run a new length of wire. I had to replace the run of wire to my last light, as it didn't quite reach.

I placed the junction box 3/4" up from the bottom of the joist and marked two holes in the back of the box with a pencil. Drywall screws hold the box in place. You'll need one box for each light. Whenever you have a splice in wire, you need a junction box with strain relief.
I didn't remove any knockouts yet.

The junction box prior to the cover installed.

The lights are 4' long with the chain 6" inset at each end. I drilled the hole for the chain 1.5" off the bottom of the joist and screwed through the chain link with the light tight to the bottom of the joist.
Doing this by myself, I screwed one end of the chain with more slack than I needed so I could screw in the other side and then readjust the first side. The lights are tight to the bottom of the joist, or have a minimal amount of gap.

A screw through the chain of the light.

These lights come ready to plug into a receptacle, so you'll need to cut the end off. Measure first to make sure you have enough cord. I generally cut the cords 18" long, but had to cut them longer in a few places. Run it to the junction box to determine the length you need. Make it 4-6" longer than the junction box so you have room to splice it. Strip the light's wire and determine which side of the adjacent junction box it will run through.
Remove the knockout and screw in a strain relief connector. For the knockout, I hit it with a hammer then use pliers to twist it off and out. To get the strain relief tight, I would have the screws of the strain relief at the top or bottom depending on side, tighten the nut by hand, then twist the connector to tighten it further. Run the light wire into the box through the strain relief Don't screw the strain relief down yet, as you still need to run power from the existing light.

Wiring & Finishing
With all the new lights and boxes installed, it's time to cut the power. With the lights off there is no power to the old light fixtures, but flipping the breaker too is the best practice. Double check with a test light that the power is indeed off. I ran a portable light from a receptacle on a different breaker so I'd have light to work.

Remove the old fixtures, but don't cut the wires. I unscrewed the incandescent bulb fixture from the plastic junction box then removed the wires with a screw driver. A hammer and pry bar were used to remove the boxes which were typically nailed into the joist.

Existing fixture and plastic junction box.

Back side of the fixture with the wire terminals.

I ran the existing power wire and new light wire into just one knockout. That way I only use one strain relief connection per box. For my light that has the power coming in, I used two strain relief as I had the power wire, splits to two different lights, and the light fixture cord. That just wouldn't fit into one connection.

A knockout removed.

Run the wires through the strain relief opening and tighten it down. I make sure there are a few inches of slack in the wire from the light to the box. The strain relief ensure the wires will never be pulled out of the box or pulled apart. Without this, you have the potential for an electrical fire. The junction box is a further safeguard, to contain any shorts, sparks, etc. I've seen connections only taped, but wire nuts ensure the ends of the wire don't poke through the tape.

Strain relief installed in the junction box.

The existing wires should already be stripped, but you may need to clip the ends if they are too bent and strip further down the wire. Strip the light fixture wires. I typically strip 1/2" off the wire, then  I tape the two (or more) wires I'm connecting together with electrical tape, then twist them together slightly with pliers. Wire nut them. If you're just joining two wires, an orange wire nut is fine. If you're joining three or four, use a yellow wire nut.
Connect the black wires to black, white to white, and ground which is typically a bare wire or green to the matching wire. While the light fixture has the ground wire in a green jacket, the other two wires are not color coded. With a house being alternating current, you can't wire the light wrong as long as you get the ground correct. Alternating current means electricity flows through both wires.

I had to use two knockouts with power and two branches off this box.
Connecting four wires required yellow wire nuts.

Make sure the wire nut is tight and sized correctly. You can always tape the wire nut, but I didn't. If it's sized correctly it will stay in place. Once everything is in place, put the wires into the box and screw the cover on. If you don't twist the wires and have good contact, pushing the wires in the box could loosen the connection. That's why I give the wires a slight twist together before capping them.
You'll have to force the wire into the box as it's solid strand, but that's okay.

Installation complete and junction box cover installed.
The light and power wires are on the right, the run of wire to the next light
is on the left.

I did this six times, flipped the breaker back and then flipped the switch. All lights worked and it was finally nice and bright in my shop.

Troubleshooting:
If you have lights that don't come on, flip the switch and breaker off.

Whatever light is not on, check the connections at that junction box. Undo the wire nut, make sure the wires are properly twisted together and are making good contact with each other. Put the wire nut back and make sure it's tight.  Flip the breaker and switch. If this doesn't work, check the junction box at the next light closer to the power origin.


If your lights worked before, the likely explanation for them not working is a bad connection, either at that light or the light feeding it.

If you're convinced it's the light, with the power off, separate you power and neutral wire, removing the wire nut. Flip the breaker and test the wires directly with a test light. Do NOT touch the wires together.